How to reveled WiFi password in connect environment

In online world, it is very difficult to remember all the passwords you are using. Your computer is connected to WiFi network that you are using for a long time, and forgot the password for as long time it was not needed. Now you want to connect your mobile device or tab to the same WiFi network, you need the password for your current network. So how you will reveled the password? Here is the best solution on windows environment.